This invention relates generally to the field of medical devices used to support a portion of a patient""s body in a desired position and alignment during a medical imaging procedure, such as a CAT scan or MRI. More particularly, the invention relates to any such devices which comprise pads, pillows or similar mechanisms which are configured to support the patient""s spine or joints in either flexion or extension while the patient is supine on the gantry, platform or table of medical imaging equipment, and which further provide a recess or compartment for receiving secondary coils disposed adjacent the patient""s body part of interest such that the secondary coils do not impart undesired flexion or extension of the body part.
A number of medical imaging devices utilizing x-rays, magnetic resonance imaging (MRI), computerized axial tomography (CAT) and the like are used in detecting, documenting and diagnosing injuries or defects in a patient""s joints or spine. Such imaging devices are often utilized to diagnose spinal injuries or defects, such as traumatic hyperextension or hyperflexion resulting from accidents or the like. In the detection, analysis and diagnosis of such spinal conditions, and especially when the cervical vertebrae or neck region is of primary concern, it is often desirable to position the cervical vertebrae in a flexed or extended alignment during imaging. This is typically accomplished by providing concave or convex pillows or pads to reposition or support the patient""s neck in a full flexion (vertebrae arched forward) or extension (vertebrae arched backward) position, which position the patient must maintain in a motionless manner during the imaging process. Such positions are uncomfortable and difficult to maintain for long periods of time, often leading to blurred imaging. Mechanical devices or support pads may also impart misalignment of the vertebrae, or may provide too much continuous support of the vertebrae, thus preventing imaging of lesions or aberrant motion of the vertebrae. In addition, where a secondary imaging coil, also called a localized, surface or volume coil, must be disposed adjacent the patient""s neck, such as in MRI, the physical presence of the secondary coil itself interferes with or prevents the patient from being able to attain and maintain a desired flexion or extension position, or prevents lesions or aberrant motion from being documented. It has also been found that some pads and mechanical devices fail to produce a proper flexion position, in that the head and chin of the patient are angled forward but the vertebrae remain substantially linear.
Previous examples of devices or equipment which attempt to address the problems and issues inherent in achieving proper positioning of the spine or joints during medical imaging procedures include for example, U.S. Pat. No. 5,577,503 to Bonutti, U.S. Pat. No. 4,400,820 to O""Dell et al., U.S. Pat. No. 5,007,425 to Vanek et al., and U.S. Pat. No. 5,305,750 to Makita. The Bonutti patent shows an imaging table or gantry having various positioning structures built into the upper surface of the table that can be raised or lowered to support various portions of the patient""s body in flexed or extended alignment as required. Because the positioning structures are of fixed location and configuration, the device is limited in its functionality and is not universally suitable as it fails to accommodate patients of different sizes. The positioning structures are hinged planar portions of the patient support table. Because the Bonutti apparatus is a table with integral components, the device does no offer a solution to the many imaging tables already in use. The O""Dell et al. patent shows a head cradle that requires strapping the patient""s head into the device, which can result in less than optimum flexion or extension of the vertebrae, and the device does not address the problem of physical interference from secondary coils. The Vanek et al. patent shows a stand that can accommodate either a secondary coil or a portion of the patient""s body, but does not address solutions to the problems discussed above. The Mikita patent shows a neck bending apparatus that also does not take into account the problems associated with misalignment from the secondary coil.
It is an object of this invention to provide a relatively uncomplicated device or set of related devices that address the problems discussed above in regard for attaining flexion and extension of the spine, and in particular the cervical spine, in a manner which is comfortable while providing sufficient support to immobilize the body portion during imaging, and further that provides a means to accommodate a secondary imaging coil such that the presence of the coil does not impart undesired alignment or misalignment in the spine during imaging. It is a further object to provide such a device or set of devices such that the device itself does not impart undesired alignment of the spine by providing too much continuous support, regardless of whether a secondary coil is utilized in the imaging process. It is a further object to provide such a device or devices having a material composition essentially invisible to the imaging equipment such that no artificial artifacts are created in the resulting images. These objects, as well as objects not expressly set forth but which will become apparent upon understanding of the disclosure to follow, are supported by the disclosure to follow.
The invention comprises a support pad or pillow, individually or comprising a set, for supporting a patient during a medical imaging procedure, and in particular for supporting the cervical vertebrae or neck area of the patient in a manner which provides for flexion or extension when the patient is supine on the table of the medical imaging equipment. The invention is suitable for use with various types of medical imaging equipment, including for example x-ray, magnetic resonance imaging (MRI), or computerized axial tomography (CAT). In particular, the invention solves problems inherent in medical imaging equipment that requires a secondary coil to be affixed to or positioned adjacent the patient""s neck.
The invention comprises a pad of sufficient rigidity to support the weight of a patient""s head, yet with some degree of cushioning effect for comfort. The pad comprises a curved support surface and a generally rectangular cavity. For disposing the cervical vertebrae in extension, the curved support surface is arched outward. For disposing the cervical vertebrae in flexion, the curved support surface is depressed inward, with one end of the pad significantly higher than the other. A depression to receive or cradle the rear of the patient""s head is provided above the cavity on the flexion pad. The cavity is disposed on the support surface of both the flexion and extension pad and provides an area of non-contact on the back of the neck such that the tissue and vertebrae are not excessively supported in a continuous manner to preclude or hinder documentation of lesions or aberrant motion, or are not distorted or misaligned by pressure from the support surface itself. The cavity further provides a space to receive a secondary coil if present, such that the coil does not interfere with the desired alignment or prevent detection of lesions or aberrant motion. The flexion and extension pads form a diagnostic imaging set, in that it is often desirable to image the vertebrae in both flexion and extension.
An alternative embodiment is also provided, wherein the extension pad can be used alone to provide extension, but also becomes a base to receive and support a flexion pad. In one embodiment, a groove is provided in the support surface of the extension pad and a corresponding tongue is provided on the underside of the flexion pad, such that the flexion pad can be interlocked with the extension pad when flexion imaging is desired.